:root{--bg:#0b1020;--card:#151b2e;--accent:#4f8cff;--text:#e7ecf5;--muted:#9aa6bd;--good:#2ecc71;--bad:#ff5d6c;--border:#243049}*{box-sizing:border-box}body{margin:0;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,PingFang SC,Hiragino Sans,sans-serif;background:var(--bg);color:var(--text);line-height:1.6}.container{max-width:760px;margin:0 auto;padding:32px 20px 80px}h1{font-size:1.6rem}h2{font-size:1.2rem}a{color:var(--accent)}.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(180px,1fr));grid-gap:12px;gap:12px;margin:16px 0}.card{background:var(--card);border:1px solid var(--border);border-radius:12px;padding:16px;cursor:pointer;transition:border-color .15s}.card:hover{border-color:var(--accent)}.card h3{margin:0 0 4px}.card p{margin:0;color:var(--muted);font-size:.9rem}.card .card-link{display:inline-block;margin-top:10px;font-size:.9rem}.question{background:var(--card);border:1px solid var(--border);border-radius:12px;padding:16px 20px;margin:14px 0}.stem{font-weight:600;font-size:1.05rem}.options{list-style:none;padding:0;margin:8px 0 0}.options li{margin:6px 0}.options label{display:flex;gap:8px;align-items:baseline;cursor:pointer}button{background:var(--accent);color:white;border:0;border-radius:10px;padding:10px 18px;font-size:1rem;cursor:pointer}button.secondary{background:transparent;border:1px solid var(--border);color:var(--text)}button:disabled{opacity:.5;cursor:default}.row{display:flex;gap:10px;align-items:center;flex-wrap:wrap}.muted{color:var(--muted)}.correct{color:var(--good)}.wrong{color:var(--bad)}.pill{display:inline-block;padding:2px 8px;border-radius:999px;font-size:.8rem;border:1px solid var(--border)}.score{font-size:2rem;font-weight:700}.feedback{border-top:1px dashed var(--border);margin-top:10px;padding-top:10px;font-size:.92rem}.chip{background:transparent;border:1px solid var(--border);color:var(--text);padding:6px 12px;border-radius:999px}.chip.active{border-color:var(--accent);color:var(--accent)}